Cast detergent-containing article and method of using

ABSTRACT

Solid cast detergent-containing articles are produced for use in automatic washing machines. A liquid detergent composition is cast into a mold where it is allowed to solidify. The solid cast detergent, surrounded on all but its upper surface by the mold, is used in automatic washing machines having a dispensing device designed to dispense a liquid aqueous detergent formed from the solid cast detergent using an impinging liquid spray. The liquid aqueous detergent flows out of the dispensing device generally simultaneously with its formation in the dispenser. The cast detergent composition includes an alkaline hydratable chemical and optionally further includes one or more preformed cores or plugs comprising an available chlorine source, a defoamer, or the like.

.Iadd.This application is a reissue of U.S. Pat. No. 4,569,781 whichissued from Ser. No. 234,940, filed Feb. 17, 1981, which is acontinuation-in-part of Ser. No. 123,956, filed Feb. 25, 1980, nowabandoned, which is a continuation-in-part of Ser. No. 875,784, filedFeb. 7, 1978, now abandoned. .Iaddend.

FIELD OF THE INVENTION

This invention relates .Iadd.to .Iaddend.a novel solid castdetergent-containing article which is particularly useful ininstitutional dishwashing machines and industrial washing machines.Another aspect of this invention relates to a method for producing thedetergent-containing article. Another aspect of this invention relatesto a method for using the detergent containing article. Still anotheraspect of this invention relates to a method of isolating reactive andincompatible components within a solid cast detergent to minimizeinteraction between them during manufacture, storage, or dispensing.

DESCRIPTION OF THE PRIOR ART

Conventional institutional and industrial spray washing machines employliquid or powdered detergents which are generally added to the wash tankby means of an automatic dispenser system. All forms of such detergents,whether liquid or solid, have stability problems and other problemsassociated with their manufacture, dispensing, or use. These problemshave been discussed extensively in prior art publications and patentliterature, and it is not practical to do anything more than summarizethese discussions. In the early days of the development of the soliddetergents, when these detergent products were relatively low inperformance compared to the products of today, the problems were lesssevere. However, the advent of high performance products, stimulated inpart by increased aesthetic and sanitary standards and a demand forshorter wash times has generally been characterized by the developmentof more complex detergent compositions which are more hazardous to theuser, less stable, and more difficult to dissolve in a satisfactorilyuniform manner.

For example, higher performance solid detergents generally means higheralkalinity (e.g. greater concentrations of sodium hydroxide)--highereven to the point of posing safety hazards to the user. Historically,detergents used for warewashing have been relatively low in alkalinity.The extensive use of aluminum trays and utensils, the presence of softmetals in wash pump impellers and other factors generally prevented theuse of high alkalinity detergents. Recently, however, there has been atrend toward the use of high alkalinity, higher performance products.This trend has been partially the result of the increased usage ofstainless steel and corrosion resistant plastics in the production ofutensils. In addition, the aforementioned increased standards andshorter wash times required by the increased volume of business ineating establishments have created a demand for these higher performanceproducts. The safety hazard of highly alkaline warewashing detergentscan be high enough to justify extraordinary means for minimizing contactbetween the user and the detergent composition.

In addition to alkali metal hydroxides (e.g. sodium hydroxide),chemicals used in high performance products, particularly for hardsurface cleaning (e.g. warewashing) include phosphates, silicates,chlorine containing-compounds, defoamers and organic polyelectrolytepolymers. See U.S. Pat. No. 3,166,513, issued Jan. 19, 1965 (Mizuno etal), U.S. Pat. No. 3,535,285, issued Oct. 20, 1970 (Sabatelli et al),U.S. Pat. No. 3,579,455, issued May 18, 1971 (Sabatelli et al), U.S.Pat. No. 3,700,599, issued Oct. 24, 1972 (Mizuno et al), and U.S. Pat.No. 3,899,436, issued Aug. 12, 1975 (Copeland et al). The alkali metalhydroxides in these compositions are very effective in removing moststubborn food soils, but a source of available chlorine is usuallyincluded to control food stains, such as tea and coffee stains. Thedefoamer is usually included to control foam created by a proteinaceoussoil and saponified fats. The use of chlorinated cyanurates as a sourceof available chlorine in detergents used to clean hard surfaces isdisclosed in U.S. Pat. No. 3,166,513, issued Jan. 19, 1965 (Mizuno etal), U.S. Pat. No. 3,933,670, issued Jan. 20, 1976 (Brill et al), U.S.Pat. No. 3,936,386, issued Feb. 3, 1976 (Corliss et al). These patentsalso describe various means for obtaining storage stable chlorinebearing detergents. The use of defoamers in detergent compositions isdisclosed by U.S. Pat. No. 3,048,548, issued Aug. 7, 1962 (Martin etal), U.S. Pat. No. 3,334,147, issued Aug. 1, 1967 (Brunelle et al), andU.S. Pat. No. 3,442,242, issued May 13, 1969 (Rue et al).

One problem associated with detergents containing both an activechlorine source and an organic defoamer has been a substantial loss ofavailable chlorine in a relatively short period of time. This problem isdescribed in a number of the above references and in the article by R.Fuchs, J. Polkowski, and Carfagno, "Agglomerated Automatic DishwasherDetergents", Chemical Times and Trends, pages 37-42 (October, 1977). Onesolution to this problem has been to absorb the organic defoamer onto aninorganic carrier particle, thus "encapsulating" the defoamer, see U.S.Pat. No. 3,306,858, issued Feb. 28, 1967 (Oberle). While a chlorinestability problem is present in low alkalinity detergents containingdefoamers, the problem is more acute with high alkalinity detergentsbecause many defoamers and chlorine-containing compounds are not stablein the presence of highly alkaline chemicals such as sodium hydroxide.

In addition to the chlorine stability problem, several additionalproblems have existed with high performance powdered detergentcompositions which have been used in institutional and industrialwashing machines. One of these problems has been caused by differentialsolubility of the detergent components. Not all of the components ofstandard detergents dissolve at the same rate or have the sameequilibrium solubilities. For example, a fine, soluble particle such assodium dichloroisocyanurate dihydrate, a common source of availablechlorine, may dissolve more rapidly than some hardness sequestrants orsurfactants, i.e. common detergent component. Thus, when a dispenser ischarged with a powdered detergent containing both of these components,the first effluent from the dispenser will usually be overrich inavailable chlorine while the last effluent before the dispenser isrecharged will usually be poor in available chlorine.

Another type of differential solubility problem exists with many commondefoamers. Many defoamers have an oily consistency and are sparinglywater soluble. When detergents containing these defoamers are dispensedfrom a conventional water-in-reservoir dispenser, the oily defoamerfloats to the top and feeds the wash tank in an erratic fashion.

Another problem may exist with a powdered detergent if its componentsare of different particle sizes and densities. Variations in particlesize and density between components may lead to segregation duringmanufacturing, shipping, and handling. Even when uniform distributioncan be achieved during manufacturing, handling and shipping may causesegregation. Segregation leads to non-uniformity in the composition ofthe detergent when it is withdrawn from the container. Agglomeration ofthe components has been used to minimize the segregation problem.However, the use of agglomeration usually requires recycling of anyparticles which are too large or too small, which can be a significantpercentage of the product.

As noted previously, it is desirable for safety and convenience tominimize contact between the user and the high-performance or highlyalkaline detergent composition, and such lessened contact can be one ofthe many benefits of automatic dispensing. In the case of liquiddetergents, it is relatively easy to provide an automatic dispensingsystem and method. For example, liquid detergents can simply be pumpedinto the wash tank or reservoir directly from their shipping containers.

Solid detergents (which can be in briquette, or, most typically, inpowdered form) present much more complicated automatic dispensingproblems. Several approaches have been devised for .[.attaching.]..Iadd.attacking .Iaddend.these problems--that is, for utilizing solidphase detergents without losing the benefits of automatic dispensing. Inone approach, detergents used in large conveyor type machines aredispensed directly from their shipping containers by means of adispensing system similar to that described in U.S. Pat. No. 3,595,438,issued July 27, 1971 (Daley et al). The shipping container is invertedand placed over a detergent dispenser reservoir and a water spray isused to dissolve the detergent from the drum as needed. A system fordissolving powdered detergent from a five to ten gallon capacityshipping pail is also known, see U.S. Pat. No. 4,020,865, issued May 3,1977 (Moffat et al). In short, the solid powdered detergent in theshipping container is not in a form which normally would be introduceddirectly into the wash tank of the washing machine, and it is generallypreferred in the art to convert the powder into a liquid, e.g. bydissolving the powder with water in a special apparatus designed tocarry out the dissolving step.

The dissolving apparatus need not be physically remote from the washingmachine. Indeed, it is a common practice to mount dissolving/dispensingdevices directly above--or on the side wall of--the wash tank of themachine. One typically used type of machine-mounted dispenser is theso-called water-in-reservoir type. (The water-in-reservoir approach isnot limited to machine-mounted dispensers, however; in machine-mountedapplications, the water-in-reservoir dispenser is generally used insingle tank warewashing machines.) Typically, the water-in-reservoirtype of dispenser makes up a concentrated solution of detergent from thepowder in the reservoir by means of swirling action or agitationprovided by incoming water. The concentrated solution is delivereddirectly to the wash tank by gravity or through a delivery tube. Theconcentration of the detergent in the wash tank can be maintained at a.[.present.]. .Iadd.preset .Iaddend.level by means of a conductivitysensing controller similar to that described in U.S. Pat. No. 3,680,070,issued July 25 1972 (Nystuen).

Various other types of devices will dissolve and dispense powdereddetergents and can be mounted directly on the washing machine. Forexample, U.S. Pat. No. 4,063,663, issued Dec. 20, 1977 (Larson et al)described a type of dispenser in which the powdered detergent is placedover a conical or hemispherical screen and an aqueous spray from beneaththe screen is used to dissolve the detergent. The concentrated solutionproduced by the spray is collected and directed to the wash tank. Thedispenser differs from the water-in-reservoir type in that there is nowater standing in the powder dispenser and the bulk of the powderremains dry. Otherwise, this type of dispenser operates in a mannersimilar to the water-in-reservoir type.

Among the other types of powdered detergent dispensers are smalldispensers which hold from four to six pounds of detergent. The hopperof such dispensers can be filled from detergent-containing drums bymeans of a scoop or by the use of small individual (i.e. two pound)pouches of detergent. Dispensing systems for washing systems consistingof multiple hoppers which are filled with different chemicals ormixtures of chemicals are also known.

Dispensing systems for dispensing briquettes of detergent are also knownin the art. See U.S. Pat. Nos. 2,382,163, 2,382,164, 2,382,165 allissued Aug. 14, 1945 to MacMahon and U.S. Pat. No. 2,412,819, issuedDec. 17, 1946 .[.(MachMahon).]. .Iadd.(MacMahon).Iaddend.. The detergentbriquettes are dispensed from a modified water-in-reservoir round,pot-shaped dispenser. The briquettes (usually three) are held in a meshbasket which forms a slot about 11/4 inches wide across the diameter ofthe pot. The dissolving action is provided by a stream of water directedagainst the lower-most briquette and from the swirling action of wateraround the submerged portion of the lowermost briquette. Like thewater-in-dispenser type devices, water is left standing in thereservoir. This type of system has the advantage of making it visuallypossible to determine when the detergent dispenser reservoir needsreplenishing.

The MacMahon patents also disclose detergent briquette compositions andmethods of manufacturing the briquettes. The briquette compositions andthe methods of manufcture which are disclosed appear to require thepresence of a silicate and trisodium polyphosphate or sodium carbonate.Detergent bars or cakes comprising a significant level of an organicdetergent and tripolyphosphates are also known. See U.S. Pat. No.3,639,286 issued Feb. 1, 1972 (Ballestra et al). Compressed tabletscontaining detergents are also known, see U.S. Pat. No. 2,738,323,issued Mar. 14, 1956 (Tepas, Jr.) and U.S. Pat. No. 3,417,024, issuedDec. 7, 1968 (Goldwasser).

In the field of dispensing solid detergent .[.to.]. .Iadd.into.Iaddend.conventional institutional and industrial washing machines forspray cleaning of hard surfaces (e.g. warewashing), the briquettedetergent approach does not appear to have attained the same degree ofcommercial success as powdered detergents.

When one leaves behind the field of high performance or highly alkalinedetergents, one finds that a variety of dispensers and containers forordinary soap, compressed detergent, powder, or the like have beendisclosed. See, for example, U.S. Pat. Nos. 2,686,080 (Wood), issuedAug. 10, 1954 and 2,920,417 (Wertheimer) issued January, 1960.

SUMMARY OF THE INVENTION

It has now been found that the chlorine stability, differentialsolubility, segregation, and safety problems described above can beminimized by forming a solid cast detergent in a disposable mold anddispensing or using the detergent directly from the mold/cast detergentcombination. That is, the combination of the cast detergent and thedisposable mold in which it was formed provides an article of commercecapable of dispensing dissolved solids from substantially only onesurface--the surface which was the free or unsupported surface in themold. This detergent article can be designed or structured to furtherminimize chlorine stability and differential solubility problems, e.g.by including the chlorine source and/or the defoamer as preformed plugsor cores encased in the cast detergent composition.

Thus, the present invention involves a process for forming and a methodfor using a three-dimensional, solid cast detergent compositioncontaining an alkaline hydratable solid component, at least one othersolid component, and a receptacle-shaped mold surrounding and containingthe detergent composition on all but one surface. The detergentcomposition is normally formed by mixing and heating the components inan aqueous solution, thickening the solution and preferably also coolingit, pouring the solution into a mold, and allowing the mixture tosolidify, it being understood that the solidification can involve one ormore physico-chemical mechanisms, including "freezing", precipitationfrom solution. etc. The aforementioned preformed plugs or cores ofadditional components can be inserted in the mixture after it has beenadded to a mold and before it has solidified.

The cast detergent composition is preferably left in the disposable moldin which it was cast. Alternatively, the cast detergent can be demoldedand inserted in an inexpensive container or receptacle which hassubstantially the same configuration as the mold, since in either casethe cast detergent is surrounded on all but one surface, as describedpreviously. The thus-surrounded cast detergent is used by placing itsexposed surface in a drainable position (preferably fixed) within adetergent dispensing apparatus. A fixed drainable position is one inwhich the aforementioned unsurrounded, exposed surface is fixed withrespect to the horizontal and a potential impinging spray of liquid suchthat the unsurrounded, exposed surface permits gravity flow therefrom,either because of an inclination from the horizontal by a few degrees(e.g. by 10°-90°) or by inclination beyond 90°, i.e. partial or totalinversion up to and including a totally inverted or downward-facingposition. A spray of liquid impinging on the drainable (inclined orinverted) surface, suitably controlled in duration, provides a drainingaction or gravity flow of liquid detergent which drains downward off ofthe drainable surface to the washing machine into which the detergent isto be dispensed. Control over the duration of impingement (hence theduration of downward flow) has the effect of controlling theconcentration of detergent in the washing machine. The dispensingapparatus is not a water-in-reservoir type, since it dispenses the flowof liquid detergent about as fast as this flow is formed by the sprayingaction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial cut-away side view of a disposable mold containingthe cast detergent of this invention.

FIG. 2 is a cross sectional view of a disposable mold containing thecast detergent of this invention. The cast detergent includes apreformed plug or core comprised of an additional ingredient oringredients.

FIG. 3 is a plan view of the article illustrated in FIG. 2.

FIG. 4 illustrates the article of FIGS. 2 and 3 placed in an apparatusfor dispensing the detergent composition.

FIG. 5 is a graph comparing the chlorine recovery for a cast detergentprepared according to this invention versus a conventional powdereddetergent.

FIG. 6 is a view in perspective of a solid detergent dispenserconstructed according to the principles of this invention.

FIG. 7 is an exploded view in perspective of one embodiment of thecartridge-type receptacle member for holding a charge of solid blockdetergent as disclosed in FIG. 6.

FIG. 8 is a view in front elevation with portions thereof broken away,of the solid detergent dispenser disclosed in FIG. 1.

FIG. 9 is a sectional view of the solid detergent dispenser disclosed inFIG. 9, taken generally along the line 9--9 of FIG. 8.

DETAILED DESCRIPTION Raw Materials

One necessary component for producing cast detergent compositions of thepreset invention is a hydratable chemical. The term "hydratablechemical" as used herein includes chemicals forming both discrete andcontinuous states of hydration and thus means a chemical which iscapable of absorbing or combining with water (e.g. 0.2-20 moles of waterper mole of chemical) to form either type or stage of hydration. Thehydratable chemical will normally be alkaline, that is, a oneweight-percent aqueous solution of the chemical will have a pH ofgreater than 7.0 at 23° C. Since the detergent compositions used in thisinvention are highly alkaline, it is preferred that the hydratablecomponent of the composition be alkaline in nature. Hydratable chemicalsuseful in the practice of this invention include alkali metalhydroxides, such as sodium hydroxide and potassium hydroxide; silicates,such as sodium metasilicate; phosphates, particularly phosphates of theformula M--PO₃ M--OM or the corresponding cyclic compounds ##STR1##wherein M is an alkali metal and n is a number ranging from 1 to about60, typically less than 10 for cyclic phosphates, typical examples ofsuch phosphates being sodium or potassium orthophosphate and alkalinecondensed phosphates (i.e. polyphosphates) such as sodium or potassiumpyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate, etc.;carbonates such as sodium or potassium carbonate; borates, such assodium borate; etc. Combinations of two hydratable chemicals, forexample, sodium hydroxide and sodium tripolyphosphate, and combinationsof alkaline condensed phosphates with organic sequestering agents and/oralkali metal hydroxides have been found to work particularly well in thepractice of this invention.

A second necessary component of the detergent compositions of thisinvention is water. Water is used to form a uniform medium (solution ordispersion) containing the detergent components; the uniform mediumbeing cast into a mold and solidifying by a solidification mechanismdescribed previously. Water may be added as a separate ingredient or incombination with one of the other components, for example as an aqueoussolution of 50% sodium hydroxide.

To obtain the advantages of this invention, at least two solidcomponents are needed. If only one solid component were used,differential solubility and segregation problems would not exist andthere would be few advantages to forming a cast composition. Theadvantages of a cast detergent composition over a conventional powdereddetergent composition are described more fully hereinafter.

In addition to those components previously described, other conventionaldetergent components and fillers can be included. For example, it iscommon to include a source of available chlorine and a defoamer. Manychlorine sources can be used including chlorinated isocyanurates, suchas sodium dichloroisocyanurate dihydrate, and hypochlorites, such ascalcium and lithium hypochlorite. As more fully hereinafter described,when an available chlorine containing component is included in thecomposition of this invention it is preferably incorporated in thecomposition as a preformed plug or core. Defoamers are also normallyincluded in a detergent compositions. Typically, a "defoamer" is achemical compound with a hydrophobe/hydrophile balance suitable toreducing the stability of protein foam. The hydrophobicity can beprovided by an oleophilic portion of the molecule (e.g. an aromaticalkyl or aralkyl group; an oxypropylene unit or oxypropylene chain, orother oxyalkylene functional groups other than oxyethylene, e.g.tetramethylene oxide). The hydrophilicity can be provided withoxyethylene units or chains or blocks and/or ester groups (e.g.organophosphate esters), salt-type groups, or salt-forming groups.Typically, defoamers are nonionic organic surface-active polymers havinghydrophobic groups or blocks or chains and hydrophilic ester-groups,blocks, units, or chains, but anionic, cationic, and amphotericdefoamers are known. For a disclosure of nonionic defoaming surfactants,see U.S. Pat. No. 3,048,548, issued Aug. 7, 1962 (Martin et al), U.S.Pat. No. 3,334,147, issued Aug. 1, 1967 (Brunelle et al), and U.S. Pat.No. 3,442,242, issued May 13, 1969 (Rue et al). Phosphate esters arealso suitable, e.g. esters of the formula RO--PO₃ M--_(n) R, wherein nis as defined previously and R is an organic group or M (as definedpreviously), at least one R being an organic group such as oxyalkylenechain. If a defoamer is included it may be included as a preformed plugor core, as more fully described hereinafter. If it is included as apreformed core or plug it must be a solid, or be capable of beingcombined with other components to form a solid, at room temperature.Wax-like materials can be used to further isolate the chlorine source ordefoamer in the core from the surrounding cast article.

The Detergent Composition

The hydratable chemical or combination of hydratable chemicals willnormally comprise at least 30%, and preferably 60%, by weight of thecast detergent composition. The water of hydration will normallycomprise more than 5 weight-% (e.g. 10-35 weight-%) of the castdetergent composition. Stated another way, the water of hydration cancomprise more than about 15 parts by weight per 100 parts by weight (15phr), e.g. 25-90 phr. of the hydratable chemical or combination ofchemicals. Performance-improving additives such as available chlorineproducing components and defoamers will normally comprise minor amountsof the composition, that is, less than 5%. As will be explainedsubsequently, the cast detergent composition can also contain apolyelectrolyte.

Typical three-component compositions of this invention can be formulatedfrom (1) a phosphate or other hardness-precipitating or hardnesssequestering agent, (2) an alkali metal hydroxide, and (3) water.Typical four or five component compositions would further include adefoamer and/or a neutral inorganic salt (alkali metal halides,sulfates, etc.) and/or a chlorine source and/or a thickening agent,thixotrope, suspending agent or organic chelating or sequestering agent,or the like.

Typical detergent compositions of this invention employ a condensedalkali metal phosphate for the sequestering of hardness (Mg⁺⁺ and Ca⁺⁺ions). However, organic chelating or sequestering agents (citric acid,polyelectrolytes such as the polyacrylates of molecular weight1000-3000, etc.) have been used as alternatives to or in combinationwith the condensed phosphates; see, for example, U.S. Pat. No.3,535,285, issued Oct. 20, 1970 (Sabatelli et al), U.S. Pat. No.3,579,455, issued May 18, 1971 (Sabatelli et al), U.S. Pat. No.3,700,599, issued Oct. 24, 1972 (Mizuno et al). As is known in the art,polyacrylates (particularly alkali metal salts of polyacrylic acid andits copolymers) can function as thickeners in aqueous systems. Castdetergent compositions of this invention can contain up to 15% by weightof polyelectrolytes, as the sole sequestering agent or in combinationwith alkali metal condensed phosphates.

One embodiment of the solid, cast detergent-containing article of thisinvention is generally shown by 1 in FIGS. 1 through 3. The articleincludes .Iadd.a .Iaddend.disposable container or mold 3 into which basedetergent 2 was cast or allowed to solidify. During shipping, article 1will normally include lid or cover 5. Lid or cover 5 can be made of thesame or similar material as used to make mold 3. As will be explainedsubsequently, this material is ordinarily alkaline-resistant,non-breakable, and inexpensive. Expensive corrosion-resistant metals orplastics can be used, if provision can be made for their recycling, but"disposable" materials would normally be preferred for mostinstitutional uses. As illustrated in FIG. 2, the cast detergentcomposition is surrounded by and in contact with mold 3 on all but theupper surface of the solid cast detergent. A cross-section of the solidcast detergent 2 can be more than a centimeter thick (e.g. 2-20 cmthick). The area of the upper surface can easily exceed 100 cm², e.g.125 cm² to 1000 cm² or more. Unlike compressed detergent tablets, it hasbeen found that cast detergent blocks can be made very large--almost anydesired size.

In one embodiment of this invention, cast detergent base 2 will includeone or more preformed plugs or cores 6, as illustrated in FIGS. 2 and 3.At least one preformed plug will normally comprise a chlorine source.When a plurality of preformed plugs are used they will normally comprisedifferent, incompatible ingredients. For example, one plug couldcomprise a chlorine source while a separate plug could comprise adefoamer. By incorporating a chlorine source in one preformed plug and adefoamer in a separate preformed plug, degradation of the chlorinesource, and the resultant loss of available chlorine, which often occurswhen chlorine sources and defoamers come in contact, can be minimized.Thus, by incorporating preformed plugs of incompatible ingredients inthe solid, cast detergent composition of this invention, the stabilityproblems associated with many conventional powdered detergents can beminimized. To minimize reactivity between the base detergent and anymaterial added as preformed cores, the core material may be optionallyencased in a film or material which would not react with the corematerial or the detergent base. This coating could be comprised of anatural wax, a synthetic wax, a phosphate ester, or the like.

Some active chlorine sources such as calcium hypochlorite have beenfound to react very slowly at the .[.plug-basc.]. .Iadd.plug-base.Iaddend.detergent interface and would not normally need to be encasedin a film or the like. However, other chlorine sources such as sodiumdichloroisocyanurate dihydrate have been found to be more reactive, inwhich case a protective film would be beneficial.

Mold or container 3 can be made of any alkali-resistant material whichcan withstand moderately elevated temperatures, e.g. 150° F., and whichcan be formed into and hold the desired shape. Since the mold isgenerally intended to be "disposable" (i.e. not intended for re-use as amold), inexpensive materials are preferred such as thermoplastics,resin-impregnated heavy paper or cardboard, and the like. Inexpensivebut fragile material such as glass or ceramics are less preferred due tohandling or shipping problems, relatively flexible materials beingpreferred. Molds made of plastic (e.g. inexpensive thermoplastics) havebeen found to be particularly useful.

The solid, cast detergent-containing article of FIGS. 1-3 can be used asillustrated in FIG. 4. FIG. 4 illustrates detergent dispensing apparatus10 which can be part of a conventional institutional or industrialwashing machine (not shown). Article 1, including base detergent 2,preformed core 6, and container 3 is placed in a totally downward-facingor totally inverted position over spray means 12 which is connected to awater source 14, whereby the exposed surface of detergent 2 becomes adrainable surface. When water source 14 is turned on, spray means 12causes water to impinge on the exposed surface of detergent 2 and core6. The detergent and the core dissolve, creating a gravity flow ofliquid aqueous detergent which flows downwardly through pipe 13 to thewash tank or washing zone of the washing machine (not shown). Detergentbase 2 and preformed core 6 can be formulated to dissolve atsubstantially the same rate and thus supply the tank with a consistentratio of ingredients.

By controlling the spray time the amount of detergents, and thereby theconcentration of detergent, in the wash can be controlled. In otherwords, the liquid aqueous detergent formed as a result of theimpingement of the spray on the exposed surface of detergent 2 flows bygravity into pipe 13 generally simultaneously with its formation withindispensing apparatus 10. Standing water or aqueous liquid is notpermitted to accumulate within dispensing apparatus 10.

Referring to FIGS. 6 through 9 there is generally disclosed at 20 adetergent dispenser for solid detergent compositions of the block type,generally constructed according to the principles of this invention.That embodiment of the dispenser 20 illustrated in these Figures is oneof the type suitable for servicing relatively smaller wash applications,wherein the detergent dispenser is generally mounted directly to thewashing machine or immediately adjacent thereto, such that theconcentrated detergent solution formed by the dispenser apparatus willflow by gravity into the wash tank of the washing machine proper (notillustrated).

The dispenser 20 has a housing portion 21, constructed of any suitablematerial capable of withstanding exposure to highly caustic detergentsolutions, and is preferably configured of stainless steel or moldedplastic material. The housing 21 has a generally planar back wall 21asuitable for direct engagement with and mounting to a vertical mountingsurface or wall (not shown). The back wall 21a includes a plurality ofmounting slots 22 formed therethrough, to enable fixed mounting of thehousing 21 to a solid vertical surface such as a vertical wall of awashing machine or a vertical wall disposed adjacent a washing machine.

The housing 21 defines a substantially enclosed inner cavity 30. Forease of reference and distinguishing the various portions of the innerhousing cavity 30, referring to FIG.9, the upper portion of the innercavity will be referred to as the spray region 30a of the cavity, andthe lower portion of the inner cavity 30 will be referred to as thecollector or discharge region 30b thereof, it being understood thatgravity flow prevents detergent liquid from standing or accumulating inthe collector or discharge region 30b.

The upper portion of the housing 21 defines a mouth or access port 32opening into the inner cavity 30. Discharge region 30b includes a hoseclamp extension 35 (FIGS. 8 and 9) which defines a passageway ordischarge port 34 (FIG. 8) through the housing 21 for concentrateddetergent solution collected or accumulated within the discharge region30b of the inner cavity 30 of the housing 21. The hose clamp extension35 has a plurality of annular ribs configured for engaging the innerwalls of a connecting conduit or hose (not illustrated), for directingfluid flow from the discharge port 34 (FIG. 8).

An upper front wall 21b of the housing 21 projects downwardly from theaccess port 32 at an inclined angle to the horizontal. In the embodimentof the invention illustrated in FIGS. 6-9, the upper front wall 21bforms an angle of approximately 60 degrees with the horizontal. Theupper front wall 21b terminates at and is continuous with a first lowerwall 21c of the housing 21, which is also slightly inclined with respectto the horizontal and lies in a plane generally parallel to that of theupper front wall 21b. The lower front wall 21d terminates at and iscontinuous with a bottom wall 21e (FIG. 9) of the housing. In FIG. 9,the bottom wall 21e is generally planar, however the bottom wall 21ecould assume many different configurations (such as ramp-shaped orfunnel-shaped), and is generally configured so as to direct downward anydetergent solution formed within cavity 30 by the impingement action ofthe liquid spray from nozzle 61 (FIG. 9) on surface 100a of cast solidblock detergent 100 (FIG. 9) into discharge port 34.

The back wall 21a extends between the bottom wall 21e and an upper wall,generally designated at 21f, which extends to and defines one edge ofthe access port 32. When viewed in cross-section as in FIG. 9, thatregion of the inner cavity 30 generally located between the upper frontwall 21b, the first lower wall 21c and the back wall 21a and the upperwall 21f comprises the upper spray region 30a; whereas the region of theinner cavity 30 generally located between the lower front wall 21d andthe back wall 21a, and extending down to the bottom wall 21e generallycomprises the discharge region 30b.

The housing 21 further has a pair of oppositely disposed side walls 21g,each configured to define a flange or land region 24 extending into theinner cavity 30 in generally parallel spaced relationship to oneanother. The land regions 24 are disposed to extend from the access port32 downwardly to the bottom wall 21e, and cooperatively form with thefront wall 21b oppositely disposed channels or races within the innercavity 30 for slidably retainably engaging a cartridge member 40.

One embodiment of a cartridge member 40 suitable for removable insertionwithin the access port 32 of the dispenser 21 is illustrated in moredetail in FIG 7. Referring to FIG. 7, the cartridge 40 is basically areceptacle or container-shaped member suitable for retainably holding infixed position relative thereto a cast solid block of solid detergentcomposition. The cartridge member 40 generally comprises a bottomsurface 41, a lower peripheral side wall portion 42, an intermediateledge region 43 and an upper peripheral side wall portion 44. The lowerperipheral side wall portions 42 extend between the bottom surface 41and the intermediate ledge region 43, with all except one surface of thelower peripheral side walls (that surface designated as 42a) beingdisposed generally perpendicular to the bottom surface 41. Thenon-perpendicular lower peripheral side wall portion 42a is configuredto define an angle with the bottom surface 41 corresponding to theincluded angle defined between the upper front wall 21b and the firstlower wall 21c of the dispenser housing 21 (see FIG. 9). The fourth sideof the upper peripheral side wall 44a forms an included angle with thegeneral plane of the intermediate ledge region 43 .[.substantialy.]..Iadd.substantially .Iaddend.equal to that of the included angle formedbetween the lower front wall 21d and the bottom wall 21e of thedispenser housing 21 (see FIG. 10).

The 43a portion of the intermediate ledge region is somewhat wider (asmeasured between corresponding upper and lower peripheral side wallportions) than the width of the intermediate ledge region 43 of theother portions of the cartridge member 40. A plurality of raised landareas or mounting surfaces 45 project upwardly from the intermediateledge region 43a, the upper surfaces respectively thereof lyinggenerally in a common plane.

The lower peripheral side walls 42 and 42a cooperatively define with thebottom surface 41 a first receptacle-shaped container 46 for retainablyholding a geometrically shaped volume or mass of cast solid detergentcomposition 100 (see FIG. 9). The elongated intermediate ledge region43a defines the bottom surface of a second receptacle-shaped container,generally designated .[.at.]. .Iadd.as .Iaddend.47 (see FIGS. 7 and 9).A screen or mesh member 50 is configured for mounting to theintermediate ledge region 43 (other than at the extended intermediateledge region 43a) and to the raised mounting surfaces 45, in spacedrelationship to the underlying extended intermediate ledge region 43a,so as to overlie respectively the first and second receptable-shapedcontainer regions 46 and 47. In the preferred embodiment of theinvention, the first receptacle-shaped container 46 retainably holds asolid block of detergent composition which was cast directly into thereceptacle-shaped container portion 46 of the cartridge member 40, thecontainer portion 46 physically forms the mold in which the solid castdetergent 100 (FIG. 100) is manufactured. The retainably held charge ofsolid detergent 100 within the container portion 46 of the cartridgemember 40 defines a broad, generally planar upper surface 100a (FIG. 9)lying generally in the same plane as the intermediate ledge region 43 orslightly therebelow. The upper detergent surface 100a is inclined fromthe horizontal (hence "drainable") and is disposed for exposure to sprayfrom a nozzle means, hereinafter described in more detail.

The screen member 50 has a first generally planar portion 50a. (FIG. 7),a second generally planar portion 50b and an interconnecting wallportion 50c. The first screen portion 50a is sized to fit between theopposing upper peripheral side walls 44 and is configured for mountingto the three contiguous portions of the intermediate ledge regions 43exclusive of ledge region 43a, for substantially overlying the firstreceptacle-shaped container portion 46 of the cartridge member 40. Thesecond portion 50b of the screen member 50 lies in a plane generallyparallel to and spaced above that of the first screen portion 50a, andis configured for mounting to the plurality of raised mounting surfaces45 so as to substantially overlie the extended intermediate ledge region43a and the second receptacle-shaped container region 47 of thecartridge member 40. The interconnecting wall portion 50c of the screenmember 50a and 50b portions of the screen member 50 substantially thesame as those included angles which the lower peripheral side wallportion 42a forms with the bottom surface 41 and with the intermediateledge region 43a of the cartridge member 40. When mounted to thecartridge member 40, the interconnecting wall portion 50c of the screenmember 50 forms included angles with the first and second 50a and 50bportions of the screen member 50, substantially the same as thoseincluded angles which the lower peripheral side wall portion 42a formswith the bottom surface 41 and with the intermediate ledge region 43a ofthe cartridge member 40. When mounted to the cartridge member 40, theinterconnecting wall portion 50c of the screen member 50 lies generallyco-planar with the lower peripheral side wall portion 42a, andoperatively forms an extension thereof, to define with the extendedintermediate ledge region 43a and the upper peripheral side wall portion44a and those oppositely disposed portions of the upper peripheral sidewall 44 lying contiguous with the extended intermediate legion region43a, the second receptacle-shaped container 47.

The cartridge member 40 may be constructed of any suitable material thatis capable of withstanding exposure to highly caustic detergentsolutions, and is preferably configured of molded plastic material suchas polyethylene or polypropylene. The cartridge member can be suppliedwith solid block detergent and sold as an article of commerce, whereinthe entire cartridge member 40 or portions thereof can be discardedafter the detergent charge retainably held thereby has been exhausted.When the cartridge member is a disposable item, the screen member 50would be permanently welded or bonded to the intermediate ledge region43 and the plurality of raised land areas 45.

Alternatively, the cartridge member 40 could be a re-usable item,possibly constructed of stainless steel, wherein the screen member 50could be detachably secured to the underlying cartridge member 40 so asto enable re-charging of the solid block detergent retainably held bythe various receptacles of the cartridge member. The screen member 50may be of any suitable material capable of withstanding exposure tohighly caustic detergent solutions, and is in the preferred embodiment,preferably constructed of a plastic material. The mesh size of thescreen member 50 is configured so as to be small enough to prevent solidparticles of the solid block detergent held by the receptacle-shapedcontainers of the cartridge member 40 from passing therethrough, yetmust be large enough so as to permit relatively unobstructed passagetherethrough of a pressurized spray pattern directed at the underlyingexposed surfaces of the solid block detergent. In general, the mesh sizeof the screen member 50 should be no larger than the largest dimensionof the discharge port 34, so as to prevent any solid chunks or pieces ofthe solid block detergent which would pass therethrough from cloggingthe free flow of concentrated detergent solution through the dischargeport 34.

The first receptacle-shaped container 46 of the cartridge member 40 canbe configured to hold the solid cast detergent composition of thisinvention. The second receptacle-shaped container 47 can, if desired, beconfigured for retainably holding a long narrow block of a second solidblock detergent composition (not shown). Preferably, however, container47 is configured to hold a plurality of pillow-shaped pieces,briquettes, tablets or pellets of detergent ingredients such as achlorine source or a defoamer of the type described herein, particularlyin those cases wherein a defoamer and/or chlorine-releasing agent plughas not been inserted into the cast detergent 100. The briquette ortablet form of the detergent ingredients retainably held by the secondreceptacle-shaped container 47, is illustrated at 103 in FIG. 9. It isto be understood that, in the event that a chlorine-releasing and/ordefoamer plug or plugs were inserted in cast detergent 100, container 47could be left empty.

In the embodiment of the detergent dispenser disclosed in FIGS. 6-9, theheight and width of the cartridge member 40 are sized for cooperativeinsertion within the access port 32 of the housing 21, as illustrated inFIG. 6, whereby cartridge member 40 can be placed in a fixedpre-determined position with respect to the housing, (as indicated inFIG. 9). When disposed in such fixed, pre-determined resting position,upper detergent surface 100a (the only surface of cast solid detergent100 which is not surrounded by the walls of cartridge member 40) isexposed to any spray which may emerge from spray-forming nozzle 61.Referring to FIGS. 9 and 6, a conduit member 60 is secured to the upperwall 21f of the housing 21 and projects therethrough into the upperspray region 30a of the inner cavity 30. The spray-forming nozzle 61 isthreaded or otherwise properly secured to that end of the conduit 60extending into the inner cavity 30 and is disposed therein, so as toproject a spray pattern of pre-determined shape at substantially theentire respective exposed solid detergent block surfaces of thedetergent within the various receptacle chambers of the cartridge member40. The nozzle 61 is oriented, relative to the "fixed" position of thecartridge member 40 within the inner cavity 30, such that thelongitudinal spray axis 62 from the nozzle is disposed generallyperpendicular to the broad "drainable" exposed upper surface 100a of thesolid block detergent volume 100. The spray nozzle may be of anysuitable configuration and construction for projecting a pressurizedspray of aqueous liquid (preferably water) received through the conduit60, in a pre-determined pattern, configured to directly impinge uponsubstantially the entire exposed surfaces of the solid block detergentretainably held by the cartridge member 40. In the embodiment of theinvention disclosed in the Figures, the particularly spray nozzleproduces a "square" spray pattern (as viewed in a plane generallyperpendicular to the longitudinal spray axis 62) for directing the spraypattern ejected therefrom at substantially the entire drainable exposedsurface 100a as well as at the exposed surface or surfaces of the solidblock detergent retainably held by the second receptacle-shapedcontainer 47. The water supply conduit 60 passes through a siphonbreaker 63 (FIG. 6) and is connected, in operation, to a suitablepressurized source of water (not shown), generally ranging between 5 and70 psi.

A safety .[.switzh.]. .Iadd.switch .Iaddend.configuration is mountedwithin the housing 21 for sensing the operative position of thecartridge member 40 within the inner cavity 30, including a reed switchmember 70, mounted in a fixed position by means of a mounting bracket 71(see FIG. 9). Side wall portion 44a of the cartridge 40 contains anencapsulated magnet 72 (FIGS. 7 and 9). The positions of magnet 72 andthe reed switch 70 are such that the reed switch 70 is activated by themagnetic flux of the magnet 72 only when the cartridge member 40 hasbeen fully accepted into the inner cavity 30 of the dispenser 21 in itspre-determined fixed position (as illustrated in FIG. 9), whereby theaccess port 32 of the housing 21 is substantially closed by thepositioned cartridge member 40. As the magnet 72 is withdrawn out ofactivating proximity with the reed switch 70, the reed switch changesits energization state, providing an appropriate energizing (orde-energizing) signal to a valve (not shown) to block pressurized fluidflow through the conduit 60 to the nozzle 61.

Once the cartridge member 40 is properly inserted at its fixedpre-determined position within the inner cavity 30, the masses orvolumes of cast detergent or detergent ingredients retainably held byone or more of the various receptacles within the cartridge 40 aredissolved at a pre-determined rate, by the pressurized impinging flow ofaqueous liquid from the nozzle 61. A pressurized source of water isprovided to the nozzle 61 as commanded by appropriate control meanswithin the washing machine proper which the detergent dispenserservices. For example, for a "demand" system, an electronic controlnetwork such as described in the previously cited U.S. Pat. No.3,680,070 to Nystuen could be used to selectively provide pressurizedwater to the nozzle 61. Control over the duration of the impinging flowcontrols the amount of detergent dispensed from surface 100a andultimately the concentration of detergent in the wash tank of thewashing machine (not shown).

Once pressurized fluid flow is applied to the nozzle 61, the nozzlegenerates a pressurized spray pattern of pre-determined configuration,which is uniformly directed across substantially the entire upperexposed surface 100a of the solid detergent block 100, as well asagainst any exposed surfaces of the solid detergent ingredients 102 or103 contained within the second receptacle-shaped container 47. Thespray pattern passes through the mesh of the screen member 50 andimpinges directly upon the exposed surfaces of the retainably held soliddetergent blocks, dissolving by means of the hydraulic action of thespray itself a portion of the solid detergent blocks, at theirrespective exposed surfaces. After striking the exposed surface 100a ofthe detergent block 100, the spray (now converted into an aqueous liquiddetergent), drains or flows by gravity down the exposed surface 100a,dissolving by errosive action, further detergent at the exposed uppersurface 100a. (The inclination from the horizontal of surface 100afacilitates gravity flow.) Upon reaching the interconnecting wallportion 50c of the screen member 50, the concentrated aqueous liquiddetergent cascades over and through the solid chlorine source ordefoamer pellets or tablets 103 held within the second receptacle-shapedcontainer 47, to release a predetermined proportionate amount ofchlorine or defoamer components therefrom--all of which passes (ordrains) in solution as concentrated detergent solution to the lowercollector or discharge region 30b of the dispenser 21. The concentratedaqueous liquid detergent solution does not accumulate in region 30b butpasses by gravity through the discharge port 34 (FIG 8) within hoseclamp extension 35 (FIGS. 8 and 9) into appropriate conduit means ordirectly into an underlying wash tank or ware-washing zone. Besides theerrosive action of solution passing from the upper exposed surface 100aof the detergent mass 100, the volume of solid ingredients within thesecond .[.receptacle.]. .Iadd.receptacle.Iaddend.-shaped container 47 isfurther directly dissolved by hydraulic action from the spray projectedfrom the nozzle 61.

This invention applies to dispenser configurations wherein the nozzle 61is mounted below the exposed detergent surface, and the detergentsurface is placed at an angle beyond 90° (i.e. rotated through 90° up to180°, which would be an inverted position in which surface 100a faceddownward). In the embodiment of FIGS. 6-9, it is generally preferable toposition the nozzle 61 in a position overlying the solid detergent blockto be dissolved, and to place the exposed surface or surfaces of thesolid block detergent at an angle with respect to the horizontal(preferably between 10° and 90°), to supplement the hydraulicdissolution with the errosive dissolution caused by the solution flowingdown the exposed surface(s). In a preferred embodiment of the inventiondisclosed in the Figures, it has been found that an inclination of theexposed detergent surface 100a of approximately 60° with the horizontalprovides adequate dwell time for the downwardly flowing water, whilemaintaining a sufficiently small response time for the dispenser (i.e.that elapsed time after which the pressurized spray is projected fromthe nozzle 61 to the time in which the majority of the concentrateddetergent solution produced thereby has drained downwardly from thedischarge port 34).

The first lower wall 21c of the dispenser 21, as well as the upper andlower peripheral side wall portions 44a and 42a of the cartridge member40 are inclined slightly with respect to the horizontal (when thedispenser and enclosed cartridge member 40 are mounted in operativeposition), to insure drainage of any liquid solutions (either theprojected spray or resultant concentrated detergent solution) therefrom.Any liquid coming in contact with these surfaces is directed toward thecollector region 30b of the cavity 30.

Thus, the formation of an aqueous liquid detergent due to the flow ofliquid over surface 100a and/or pellets 103 is generally simultaneouswith the resulting downward or gravity flow, which quickly reachesextension 35 and prevents standing water build-up. Whenever the chargeof solid detergent contained within the various receptacles of thecartridge member 40 are depleted, the cartridge is rapidly replaced byslidably removing the spent cartridge from the inner cavity 30, throughthe access port 32, and simply replacing the spent cartridge with afully charged cartridge member 40. As previously discussed, thedisposable cartridge could be physically re-charged before replacementthereto into the housing 21. In such a re-usable cartridge application,it would be desirable to wrap the highly caustic detergent block beingplaced within the cartridge with a water soluble covering such aspolyvinylalcohol to protect the hands of the person handling the soliddetergent block used to charge the cartridge. Alternatively, thecartridge member 40 could be replaced by an appropriate retaining meansforming an integral part of the housing 21 and having appropriatereceptacle retaining means for retainably holding charges of solid blockdetergent in the required pre-determined position with respect to thenozzle spray pattern.

Method of Manufacturing Cast Detergent

While the following process is described with reference to specificcomponents, it should be understood that other components and similarprocesses can be used to form a detergent solution which can be castinto a mold and will solidify upon hydration of its hydratablecomponent. A particularly useful detergent composition of this inventionis formed by heating about 20-75 parts by weight of a 40-75 weightpercent aqueous solution of an alkali metal hydroxide, e.g. sodiumhydroxide, to a temperature above about 55° C., preferably 65°-85° C.Temperatures approaching 95° C. can also be used; see Examples 9 and 9Awhich follow. While other alkali metal hydroxides may be used, sodiumhydroxide has been found to be particularly useful and the followingmethod of manufacturing will be described with respect to it. Aqueoussolutions of 50 weight percent sodium hydroxide are readily commerciallyavailable. Solutions containing higher weight percents of sodiumhydroxide are also available (e.g. 73%) or can be produced by adding adesired amount of anhydrous sodium hydroxide to a 50 weight percentsolution of sodium hydroxide. An aqueous solution of sodium hydroxidecan also be prepared by mixing water and anhydrous sodium hydroxide inthe desired ratio.

After the aqueous solution of sodium hydroxide reaches a temperatureabove 55° C., preferably above 65° C., anhydrous sodium hydroxide can beadded, as illustrated in several of the Examples which follow, thepreferred amount being about 8 to about 40 parts by weight, i.e. about 8to about 40% of the weight of the total cast detergent composition. Alower temperature range (e.g. 55°-70° C.) may also be used in thisprocess, e.g. during alkali metal condensed polyphosphate addition.Typically, about 15 to about 40 parts by weight of anhydrous alkalimetal condensed polyphosphate are added to the solution. It is notnecessary to completely dissolve the alkali metal condensedpolyphosphate, since it can be suspended in the composition. After thepolyphosphate and/or optional fillers or components (the polyphosphateis a preferred ingredient), are added, the mixture can be cooled.Continuous mixing can be used during any dissolving, cooling, andthickening steps. The cooled and thickened mixture is poured into areceptacle-shaped mold to a level at least part way up the side moldingsurfaces. As the mixture continues to cool it will solidify to form acast composition. Solidification is believed to be substantially due tocooling. (This invention is not bound by any theory, however.) After ithas solidified, the cast detergent is surrounded by and in contact withthe mold on all sides except for its upper surface which remainsexposed.

After the base detergent has been poured into the mold, but before ithas solidified, preformed cores or plugs such as plug 6 in FIGS. 2 and 3may be added. When a plug is added, the base detergent is allowed tosolidify around it and retain it in place. While any shape or size plugcould be used, it is normally preferred that the plug extend to theentire depth of the base detergent as illustrated in FIG. 2. The plugshould extend the depth of the solidified detergent so that a constantratio of components can be maintained while the base detergent and theplug are dissolved during use.

An alternative method of including a separately formed plug or plugscould consist of using a mold comprising one or more smaller moldspositioned within the larger mold. The large mold would be filled withthe cast detergent base while the smaller mold or molds would containseparate compositions such as a source of available chlorine or adefoamer. The compositions could be cast into the smaller mold orpreformed as a plug and "pressed" into the mold.

The present invention will be further understood by reference to thefollowing specific Examples which are illustrative of the composition,form and method of producing the solid, cast detergent-containingarticle of this invention. It is to be understood that many variationsof composition, form and method of producing the cast detergent would beapparent to those skilled in the art. The following Examples, whereinparts and percentages are by weight unless otherwise indicated, are onlyillustrative.

EXAMPLE 1

An 8.8 pound batch (approximately 4000 grams) of a solid cast detergentof this invention was prepared using the following procedure.

Fifty-five parts by weight of a 50 weight percent aqueous solution ofsodium hydroxide were added to a laboratory mixer provided with astirring means and a heating means. The 50% sodium hydroxide solutionwas heated to approximately 55°-60° C. Nine parts by weight of anhydroussodium hydroxide were added to the solution. The solution was stirreduntil the anhydrous sodium hydroxide was completely dissolved. Theaddition of the anhydrous sodium hydroxide had the effect of forming anapproximate 57 weight percent aqueous solution of sodium hydroxide.

Thirty six parts of anhydrous sodium tripolyphosphate were added to thesolution and the solution was mixed. The tripolyphosphate did notcompletely dissolve but was held in suspension by mixing. Mixing wascontinued without heating until the solution began to thicken, which wasapproximately 10-15 minutes after the addition of the tripolyphosphate.

After the mixture had thickened but while it was still pourable, sixpounds (about 2700 grams) were poured into a receptacle-shaped mold suchas mold 3 in FIGS. 1-3, consisting of a slightly tapered cylindricalplastic container measuring about 61/2 inches (about 16.5 cm) at themajor diameter (the open end) and about 51/2 inches (about 14 cm) at theminor diameter and about 41/2 inches (about 11.5 cm) in depth. Themixture was allowed to harden in the mold which took approximately 5minutes.

The composition of the final cast product (in weight %) wasapproximately:

    ______________________________________                                        36.5%        sodium hydroxide                                                 27.5%        water                                                            36.0%        sodium tripolyphosphate                                          100.0%                                                                        ______________________________________                                    

While this product can be used as a detergent without additionaladditives, additional components can be included as illustrated in thefollowing Examples.

EXAMPLE 2

A product with the same composition as that described in Example 1, withthe exception that 1 part by weight of the 50% sodium hydroxide wasreplaced with 1 part by weight of a defoamer, was produced. The defoamerwas added following the addition of the sodium tripolyphosphate and waskept uniformly dispersed by continuous mixing until the mixture waspoured in the mold. At the time it was poured the mixture wassufficiently viscous so that a uniform dispersion was maintained.

The composition of the final cast product (in weight %) wasapproximately:

    ______________________________________                                        36%          sodium hydroxide                                                 27%          water                                                            36%          sodium tripolyphosphate                                          1%           defoamer                                                         100%                                                                          ______________________________________                                    

EXAMPLE 3

A mixture was prepared according to the procedure described inExample 1. 53.57 parts of 50% sodium hydroxide, 8.77 parts of anhydroussodium hydroxide. and 35.06 parts of anhydrous sodium tripolyphosphatewere used. The mixture was then poured into the mold described inExample 1. Before the mixture completely solidified 2-6 parts of apreformed circular "plug" measuring about 1 inch in diameter (about 2.5cm) and about 31/2 inches (about 9 cm) in length, comprising a source ofavailable chlorine, was placed approximately in the center of the mold.The length of the plug was such that it extended from the bottom of themold to the surface of the mixture. The mixture was then allowed toharden around the plug.

The composition of the solidified cast detergent (in weight %) was:

    ______________________________________                                        35.5%        sodium hydroxide                                                 26.8%        water                                                            36.1%        sodium tripolyphosphate                                          2.6%         chlorine plug                                                    100.0%                                                                        ______________________________________                                    

The available chlorine containing plug was prepared by forming acomposition consisting of:

    ______________________________________                                        59.7    parts calcium hypochlorite-65%                                                available chlorine (HTH ™ from                                             Olin-Matieson)                                                        14.4    parts Veegum ® WG (from R. T. Vanderbitt                                  Company, Inc.)                                                        25.9    parts dendritic sodium chloride                                       100.0                                                                         ______________________________________                                    

"Veegum" is a trademark for inorganic suspending agents.

After the three ingredients were mixed, plugs measuring about 1 inch(about 2.5 cm) in diameter and about 31/2 inches (about 9 cm) in length,were made by filling an appropriate size cylindrical die with thecomposition and subjecting the die to about 2,000 psi in a hydraulicpress.

Plugs containing available chlorine were produced following the sameprocedure from the two following compositions:

    ______________________________________                                        A.    100      parts Lithium Hypochlorite 35% available                                      chlorine                                                       B.    51.4     parts sodium dichloroisocyanurate                                             dihydrate                                                            14.4     parts Veegum  ® WG                                               34.2     parts dendritic sodium chloride                                      100.0    parts total                                                    ______________________________________                                    

Plugs produced from these formulas were also found to performsatisfactorily in the article of this invention.

EXAMPLE 4

This Example was designed to illustrate how plug 6 of FIGS. 2 and 3could be further isolated from the base detergent. One plug was madefrom each of the following formulas by compression molding at about 2000psi mold pressure.

    ______________________________________                                        41.0 g (59.9%)  calcium hypochlorite-65%                                                      availabe chlorine                                             10.0 g (14.3%)  Veegum ® WG                                               18.0 g (25.8%)  dendritic salt                                                69.9 g (100%)                                                                 41.5 g (59.7%)  sodium dichloroisocyanurate                                                   dihydrate                                                     10.0 g (14.4%)  Veegum ® WG                                               18.0 g (25.9%)  dendritic salt                                                69.5 g (100%)                                                                 ______________________________________                                    

Both plugs were dipped in melted paraffin wax which was held at justabove its melting point of 56.5° C. so that a very thin coating ofparaffin wax was formed on the sides and one end of the plug. The waxwas allowed to cool and harden. The plugs were then inserted into thecast detergent base of Example 2 following the procedure of Example 3.No visual indication of any reaction at the plug-detergent baseinterface was noted with either of these plugs.

EXAMPLE 5

A mixture was prepared following the procedure described in Example 2.52.57 parts of 50% sodium hydroxide, 8.77 parts of anhydrous sodiumhydroxide, 35.06 parts of anhydrous sodium tripolyphosphate and 1 partdefoamer were used. The mixture was then poured into the mold describedin Example 1. Before the mixture completely solidified, 2.6 parts of achlorine containing plug similar to those described in Example 3 wasadded as described in Example 3.

The composition of the solidified cast detergent was:

    ______________________________________                                        35.0%        sodium hydroxide                                                 26.3%        water                                                            35.1%        sodium tripolyphosphate                                          1.0%         defoamer                                                         2.6%         chlorine plug                                                    100.0%                                                                        ______________________________________                                    

EXAMPLE 6

A solid cast detergent of the same formula as that described in Example5 was produced. However, instead of mixing the defoamer with the basedetergent it was added in the form of a plug. Thus, two plugs were used,one comprising a defoamer and the other comprising a source of availablechlorine. The two plugs were placed near the center of the mold afterthe detergent was added, but before it solidified.

The composition of the solidified cast detergent was:

    ______________________________________                                        35.0%        sodium hydroxide                                                 26.3%        water                                                            35.1%        sodium tripolyphosphate                                          1.0%         defoamer plug                                                    2.6%         chlorine plug                                                    100.0%                                                                        ______________________________________                                    

The defoamer plug was prepared by heating together 60 parts of a viscous(at room temperature) polyoxyalkylene glycol and 40 parts of a solidmixture of mono- and di-alkyl phosphate esters until the phosphateesters melted and then mixing until the mixture .[.as.]. .Iadd.was.Iaddend.uniform. The solution was then poured into a cylindrical moldand allowed to cool and form a solid plug at room temperature.

Similar plugs were produced following essentially the same procedureusing: 50 parts of a polyethylene glycol, 25 parts of a polyoxyalkyleneglycol, and 25 parts of a mixture of mono- and di-alkyl phosphateesters.

EXAMPLE 7

A solid cast detergent was produced using the same formula and procedureas described in Example 2 except that the 1 part of defoamer was addedas a plug similar to those described in Example 6.

EXAMPLE 8

Approximately 6 pounds of a solid cast detergent of this invention wereprepared using the following procedure, 40 parts of anhydrous sodiummetasilicate and 39 parts of a 10 weight percent aqueous solution ofsodium hydrochlorite were added to a laboratory mixer provided with astirring means and a heating means. The solution was heated toapproximately 55°-60° C. Twenty parts of anhydrous sodiumtripolyphosphate were added to the solution and the solution mixedwithout heating until it began to thicken. After the mixture hadthickened but while it was still pourable it was poured into a moldconsisting of the dimensions described in Example 1. Before the mixturecompletely solidified, 1 part of a defoamer plug similar to thosedescribed in Example 6 was added following the previously describedprocedure.

The composition of the solidified cast detergent was

    ______________________________________                                        40%          sodium metasilicate                                              35%          water                                                            20%          sodium tripolyphosphate                                          4%           sodium hypochlorite                                              1%           defoamer plug                                                    100%                                                                          ______________________________________                                    

EXAMPLE 9

This example was designed to illustrate that the sodium tripolyphosphatecomponent of the previous Examples can be formed in-situ by reactingsodium trimetaphosphate with sodium hydroxide via the followingreaction: ##STR2##

Approximately 2200 ml of 50% aqueous sodium hydroxide was added to astainless steel, jacketed beaker equipped with a "Lightning" stirrer.Following the addition the temperature was 70° F. (21° C.). Next 1440 gof powdered trimetaphosphate was added slowly. As the temperature of themixture approached 100° F. (38° C.), cooling was applied. The remainderof the trimetaphosphate was added incrementally until the entire 1440grams had been added. During the addition a maximum temperature of 200°F. (93° C.) was reached.

Upon sitting for several minutes the mixture formed a solid which couldhave been cast into a mold and used as the solid, cast detergent of thisinvention.

EXAMPLE 9A

This Example illustrates that chlorinated trisodium phosphate may beused as the chlorine source. A solid cast detergent having the followingcomposition was prepared:

    ______________________________________                                        36.0%        caustic soda                                                     27.0%        water                                                            36.0%        sodium tripolyphosphate                                          1.0%         defoamer                                                         100.0%                                                                        ______________________________________                                    

The above mixture was prepared using the procedure as described forExample 2. The mixture was poured (about 2360 g) into the mold which hada removable 2 inch diameter cylinder placed in the center. After themixture had solidified, the 2 inch diameter cylinder was removed leavinga hollow cylindrical cavity. This hollow cavity was filled with about340 grams of molten chlorinated trisodium phosphate. The chlorinatedtrisodium phosphate solidified upon cooling below its melting point.Some reaction occurred at the interface of the plug. It is believed thatthis reaction may be reduced significantly allowing the cast detergentto cool thoroughly before the chlorinated trisodium phosphate was pouredand/or coating the cavity surface with an inert barrier such as, forexample, paraffin wax or mixed mono and dialkyl esters of polyphosphoricacid or like materials.

EXAMPLE 10

This Example was designed to illustrate the production of anon-phosphate solid, cast detergent. Forty parts of 50% aqueous sodiumhydroxide was heated to 150° F. (65.5° C.) in a jacketed stainless steelbeaker equipped with a stirrer. .[.Twnety.]. .Iadd.Twenty .Iaddend.partsof anhydrous sodium hydroxide were added and the mixture was stirreduntil a molten solution was formed. Twenty-five parts of liquid silicate(RU silicate from Philadelphia Quartz) having an SiO₂ /Na₂ O ratio of2.54 was added and resulted in the temperature of the mixture increasingto about 200° F. (93° C.). The mixture was cooled to about 150° F. (65°C.) and 15 parts of sodium polyacrylate were added slowly while stirringcontinued.

The mixture was poured into a plastic container where it solidified uponcooling.

EXAMPLE 11

The purpose of this Example is to compare the consistency of availablechlorine recovery from a cast detergent-containing article producedaccording to the instant invention and a conventional, prior art,powdered detergent. The prior art formula used consisted of a mixture ofsodium tripolyphosphate, sodium dichloroisocyanurate (a chlorinesource), sodium metasilicate, and sodium hydroxide. Sodiumdichloroisocyanurate comprised approximately 2.8% of the formula. Thecast detergent-containing article used was produced by the process andusing the formula described in Example 5. The chlorine source waspresent in the form of a plug situated approximately in the center ofthe cast base detergent. The cast detergent containing article wasdispensed from an apparatus similar to the one illustrated in FIG. 4.The prior art formula was dispensed from a water-in-reservoir dispenserof the type illustrated in FIG. 1 of U.S. Pat. No. 3,680,070, issuedJuly 25, 1972 (Nystuen).

Samples of the effluent from the dispensers were collected periodicallyand titrated for alkalinity to the phenolphthalein end point withhydrochloric acid and titrated for available chlorine with sodiumthiosulfate using the conventional iodometric titration. The influentwater temperature to both dispensers was about 71° C. (160° F.).

The amount of detergent present in the effluent was determined by thealkalinity of the effluent. The "chlorine recovered-percent oftheoretical" (CRPT) was then calculated from the formula: ##EQU1## Theresults are illustrated in FIG. 5. FIG. 5 shows that the solid castdetergent of this invention provides very uniform chlorine recovery whencompared to a prior art formulation. It is theorized that thedifferential solubility of the components of the prior art powdereddetergent is responsible for the more erratic chlorine recovery shown bythe prior art detergent.

EXAMPLE 12

This Example was designed to determine the effect of segregation duringthe manufacture of a conventional, prior art, powdered detergent. Sincethere should be no segregation with the solid cast detergent of thisinvention, (since all the components are physically locked in place) anysignificant segregation with a powdered detergent would represent adisadvantage of the powdered detergent.

The conventional powdered detergent used was the same as that describedin Example 11. This powdered detergent is commonly packaged in two-poundpackages. Seven two-pound packages from the same production batch wereselected at random for analysis. Ideally each of the packages shouldcontain the same percentage of each of the four ingredients.

The contents of each of the packages were weighed and the entirecontents dissolved in an appropriate quantity of water in a 30 gallondrum to give a 1% weight/volume solution. This eliminated any variationdue to the possibility of different amounts of detergent being presentin different packages. A 100 ml sample was withdrawn from each drum andtitrated for available chlorine with sodium thiosulfate using thestandard iodometric titration. The results were as follows:

    ______________________________________                                        Sample No.  Percent Available Chlorine                                        ______________________________________                                        1           1.63                                                              2           2.00                                                              3           1.53                                                              4           1.56                                                              5           1.54                                                              6           1.96                                                              7           1.65                                                              ______________________________________                                    

As indicated, the percentage of available chlorine varied from 1.53 to2.00. This variation is in part due to segregation during mixing andpackaging of the powdered detergent. This segregation is probably onefactor leading to the variation in chlorine delivery illustrated in FIG.5.

EXAMPLE 13

This Example was designed to compare the chlorine stability of castdetergents of this invention containing a chlorine source directly inthe base detergent with cast detergents of this invention whichincorporate a chlorine source as a core or plug, such as those describedin Example 3. Three different chlorine sources were used: sodiumdichloroisocyanurate dihydrate (NaDCC-2H₂), lithium hypochlorite(LiOCl), and calcium hypochlorite (Ca[OCl]₂). All of the compositionswere produced following the procedure of Example 1 with the chlorinesource being added directly to the mixture following the addition of thesodium tripolyphosphate in one case and the chlorine being added as aplug in the other. In the third case the chlorine source plug was dippedin a paraffin wax (m.p. 52.5° F.) and in a fourth case the chlorinesource plug was dipped in mono and dialkyl ester of polyphosphoric acid,a wax like solid (m.p. 150°-160° F.). The formula used and the availablechlorine remaining after various storage times at room temperature areshown in Table I.

As indicated by Table I, when the chlorine source is added directly as acomponent of the cast detergent most of the chlorine is lost within 24hours. However, when the chlorine source is added directly as acomponent of the cast detergent most of the chlorine is lost within 24hours. However, when the chlorine source is incorporated into the castdetergent as a preformed core or plug, excellent chlorine stabilityresults with Ca(OCl)₂ and lithium hypochlorite but not with NaDCC-2H₂ O.When the chlorine source plug was coated with a film of paraffin wax ora waxy mono and dialkyl ester of polyphosphoric acid the beststabilities were obtained.

                                      TABLE I                                     __________________________________________________________________________                CHLORINE SOURCE ADDED DIRECTLY                                                TO DETERGENT            CHLORINE SOURCE ADDED AS PLUG             Components* Ca(OCl).sub.2                                                                        LiOCl  NaDCC--2H.sub.2 O                                                                       Ca(OCl).sub.2                                                                         LiOCl   NaDCC--2H.sub.2           __________________________________________________________________________                                                        O                         NaOH - 50%  52.4   51.0   52.2      52.57   52.57   52.57                     NaOH Anhyd  9.0    9.0    9.0       8.77    8.77    8.77                      STP         36.0   36.0   36.0      35.06   35.06   35.06                     Defoamer    1.0    1.0    1.0       1.00    1.00    1.00                      Ca(OCl).sub.2                                                                             1.6    --     --        2.60    --      --                        NaDCC--2H.sub.2 O                                                                         --     --     1.8       --      --      2.60                      Li(OCl) - 35%                                                                             --     3.0    --        --      3.33    --                        .[.Percent Avaiable.].                                                        .Iadd.Percent Available.Iaddend.                                                          3.5    17.4   3.5       --      --      --                        Chlorine remaining                                                            after 24 hours                                                                Percent Available                                                                         --     --     --        --      --      --                        Chlorine remaining                                                            after 2 days                                                                  Percent Available                                                                         --     --     --        --      60      1.5                       Chlorine remaining                                                            after 15 days                                                                 Percent Available                                                                         --     --     --         98     --      --                        Chlorine remaining                                                            after 29 days                                                                 __________________________________________________________________________    CHLORINE STABILITY                                                                        CHLORINE SOURCE ADDED AS PLUG                                                                         CHLORINE SOURCE .[.ADDD.]. .Iadd.ADDED                                        .Iaddend. AS PLUG                                     BUT COATED WITH PARAFFIN                                                                              BUT COATED WITH PE-053                    Components* CaOCl  LiOCl  NaDCC--2H.sub.2 O                                                                       CaOCl   LiOCl   NaDCC--2H.sub.2           __________________________________________________________________________                                                        O                         NaOH - 50%  52.57  52.57  52.57     52.57   52.57   52.57                     NaOH Anhyd  8.77   8.77   8.77      8.77    8.77    8.77                      STP         35.06  35.06  35.06     35.06   35.06   35.06                     Defoamer    1.00   1.00   1.00      1.00    1.00    1.00                      Ca(OCl).sub.2                                                                             2.60   --     --        2.60    --      --                        NaDCC--2H.sub.2 O                                                                         --     --     2.60      --      --      2.60                      Li(OCl) - 35%                                                                             --     3.33   --        --      3.33    --                        Percent Available                                                                         --     --     --        --      --      --                        Chlorine remaining                                                            after 24 hours                                                                Percent Available                                                                         --     --     --        --      --      --                        Chlorine remaining                                                            after 29 days                                                                 Percent Available                                                                         100    99     100       --      --      --                        Chlorine remaining                                                            after 15 days                                                                 Percent Available                                                                         --     --     --        100     99      100                       Chlorine remaining                                                            after 2 days                                                                  __________________________________________________________________________     *Components shown in parts by weight. These products essentially same as      Product of Example 5.                                                    

EXAMPLE 14

The purpose of this Example was to compare the uniformity of delivery ofdefoamer from: (A) a conventional powdered detergent (Score TM, acommercial product of Economics Laboratory, Inc.); a cast detergent(product of Example 5); and (C) a cast detergent incorporating thedefoamer as a core or plug (product of Example 6). All three of theformulations contained 1% by weight of defoamer. The (A) conventionaldetergent and (B) the product of Example 5 contained the same defoamer;(C) the product of Example 6 contained the blend of two defoamersdescribed in Example 6 (the blend was used to obtain a solid productwhich could be molded into a plug).

All tests were conducted in a Hobart C-44 (trademark) single tankdishwashing machine. A C-11 Dispenser (trademark of EconomicsLaboratory, Inc.), a water-in-reservoir type dispenser, was used todispense product (A) (the conventional powdered detergent). The Hobart C44 (trademark) machine was equipped with a dispenser similar to thatillustrated in FIG. 4 for dispensing the solid .[.oast.]. .Iadd.cast.Iaddend.detergent products (B) product of Example 5) and (C) (productof Example 6), Both dispensers were contolled by a conductivity basecontroller of the type described in U.S. Pat. No. 3,680,070, issued July25, 1972 (Nystuen). The controller was set to maintain a 0.2%concentration of detergent in the wash tank. The water temperature wasabout 140° F. (65° C.) for all of the tests.

Defoamers are included in detergents for spray-wash machines to controlfoam created by food soils. Foam in a wash tank leads to entrapment ofair in the wash solution being recirculated through the machine andresults in a reduction in mass and kinetic energy which leads to poorsoil removal. Excess foam in a wash tank causes a loss in water pressurewhich can be measured by a manometer connected to the wash manifoldupstream from the water pump. Egg is a common foam-causing food soil andwas selected for use in this test.

The C-11 Dispenser originally holds about four pounds of powdereddetergent and thus four pounds of conventional detergent (A) were usedin the test. Products (B) and (C) were approximately six pounds each andwere of the configuration described in Example 1 and illustrated inFIGS. 1-4.

The pressure (in inches of water) was recorded when the dispenser wasfreshly charged, when about one-half of the detergent had beendispensed, and when about four fifths of the detergent had beendepensed. Manometer readings were taken on the freshly chargeddetergent: (1) with water alone, (2) after the detergent was added. (3)five minutes after 115 grams of egg were added, and (4) five minutesafter an additional 100 grams of egg were added.

Between the "Freshly Charged" test and the "Detergent 1/2 Spent" test,the fill valve was opened to deliver 2 gallons of water per minute fordilution to simulate normal dilution of the wash tank by rinse waterwhich is diverted to the wash tank to freshen the wash water. Theconductivity controller dispensed detergent as required to maintain a0.2% concentration of detergent in the wash tank. When about one-half ofthe detergent originally in the dispensers was left, manometer readingswere taken and the two egg additions described above repeated withreadings being taken five minutes after each addition. The sameprocedure was repeated after about one-fifth of the detergent originallypresent was left in the dispensers (four-fifths spent).

The "Detergent 1/2 Spent" test was somewhat more severe than the"Freshly Charged" test and, likewise, the "Detergent 4/5 Spent" test wassomewhat more severe than the "Detergent 1/2 Spent " test, due to thecumulative concentration of egg soil resulting because the wash tank wasnot drained between tests.

The results of these tests are summarized in Table II.

                                      TABLE II                                    __________________________________________________________________________                     FRESHLY CHARGED                                                                           DETERGENT 1/2 SPENT                                                                        DETERGENT 4/5 SPENT                                  Wash Pressure                                                                          %  Wash Pressure                                                                          %   Wash Pressure                                                                           %                                          (inches of water)                                                                      Loss                                                                             (inches of water)                                                                      Loss                                                                              (inches of water)                                                                       Loss                      __________________________________________________________________________    (A)                                                                              Conventional Powdered                                                         Detergent                                                                     Water alone:  43       -- --       --  --        --                           Detergent added:                                                                            43       -- 42.5     --  41.0      5.0                          5 minutes after 115 g.                                                                      38       12 26.0     40  25.0      42                           egg added:                                                                    5 minutes after additional                                                                  28       35 22.0     48  *         --                           100 g. egg added:                                                          (B)                                                                              Defoamer in Cast Detergent                                                    (Product of Example 5)                                                        Water alone:  42       -- --       --  --        --                           Detergent added:                                                                            42       -- 43       --  42.5      --                           5 minutes after 115 g.                                                                      42       0  43        0  41.0      3.0                          egg added:                                                                    5 minutes after additional                                                                  42       0  30       30  29.0      32                           100 g. egg added:                                                          (C)                                                                              Defoamer as Plug in Cast                                                      Detergent (Product of                                                         Example 6)                                                                    Water added:  42.5     -- --       --  --        --                           Detergent added:                                                                            42.5     -- 42       --  42.5      --                           5 minutes after 115 g.                                                                      42.5     0  42        0  41.0      0                            egg added:                                                                    5 minutes after additional                                                                  42.5     0  42        0  41.0      3.5                          100 g. egg added:                                                          __________________________________________________________________________     *Test was stopped due to excessive foam to avoid damage to pump and motor                                                                              

The data in Table II indicates that Product (C) the product of Example 6with the defoamer included as a plug) had the highest and mostconsistent wash pressures and that Product (B) (the product of Example 5with the defoamer included in the cast detergent) had higher and moreconsistent wash pressures than Product (A) (the conventional powdereddetergent). The higher and more consistent wash pressures indicate moreuniform defoamer delivery.

It was noted that the defoamer incorporated in the powdered detergent(A) floated to the top and formed an oily film in the water-in-reservoirdispenser. It is believed that this resulted in slug-feeding of thedefoamer instead of uniform delivery. In contrast, with the solid castdetergent of this invention, both the detergent and defoamer aredispensed simultaneously which helps assure uniform dispensing of thedefoamer.

What is claimed is:
 1. A detergent-containing article of commercecomprising:(a) a three-dimensional, solid.Iadd., .Iaddend.cast,hydrated, substantially uniform alkaline detergent .Iadd.for ware andhard surface washing .Iaddend.comprising:(1) at least .Iadd.about.Iaddend.30% by weight of an alkaline hydratable chemical consistingessentially of alkali metal hydroxide: (2) .Iadd.an effective amount of.Iaddend.a hardness-sequestering agent; (3) .[.more than 15 parts byweight, per 100 parts by weight of said alkaline hydratable chemical,of.]. water of hydration, at least a portion of said water of hydrationbeing associated with said alkali metal hydroxide.Iadd., wherein thealkali metal hydroxide and the hardness sequestering agent are presentin an amount sufficient to render the cast detergent a solid at roomtemperature by virtue of the water of hydration.Iaddend.; and (b) areceptacle-shaped disposble container surrounding and in contact withsaid solid, cast, hydrated alkaline detergent composition on all but onesurface thereof.
 2. An article according to claim 1 wherein saidcontainer is the mold in which said composition .[.was.]. .Iadd.is.Iaddend.cast and solidified.
 3. An article according to claim 2 whereinsaid article further comprises a cover attached to the saidreceptacle-shaped container.
 4. An article according to claim 1 whereinsaid article comprises at least one preformed core.[., said core beingsurrounded by and in contact with said detergent on at least one side ofsaid core.]..
 5. An article according to claim 4 wherein said preformedcore comprises a material selected from the group consisting of adefoamer and a solid, available chlorine-containing component.
 6. Anarticle according to claim 5 comprising a plurality of preformed cores,at least one of which comprises a solid, available chlorine-containingcomponent.
 7. An article according to claim 5 wherein .[.a.]. saidpreformed core has been coated with .[.an inert barrier.]. .Iadd.a.Iaddend.film.
 8. An article according to claim 1 wherein said solid,cast, hydrated, alkaline detergent composition comprises:(a) at leastabout 30% by weight of a first alkaline hydratable chemical consistingessentially of an alkali metal hydroxide; (b) a second alkalinehydratable chemical comprising a hardness-sequestering amount of analkali metal condensed phosphate; (c) .[.more than 5% by weight of.].water of hydration in both discrete and continuous states of hydration,at least a portion of said water of hydration being associated with saidalkali metal hydroxide; (d) .[.up to about 15% by weight of a.]..Iadd.an effective hardness sequestering amount of an organic.Iaddend.polyelectrolyte; and (e) up to 5% by weight of an additiveselected from the group consisting of a defoamer and a solid, availablechlorine-containing compound.
 9. An article according to claim 8 whereinsaid solid, cast, hydrated alkaline detergent composition furthercomprises a sodium silicate. .[.10. The detergent containing article ofclaim 1 wherein there is about 10 to 35 wt %, based on the hydratedalkaline detergent composition, of water of hydration..].
 11. A methodfor dispensing warewashing detergent into a warewashing zone for washingalkaline detergent-resistant ware, using the cast, hydrated.Iadd.,.Iaddend.alkaline detergent composition of the detergent-containingarticle of claim 1, comprising the following steps:(a) placing saidcast, hydrated, alkaline detergent composition in a detergent dispensingdevice having a spray means, in a position with respect to thehorizontal and with respect to said spray means, for dispensingdetergent downwardly from said detergent composition to the warewashingzone of a warewashing machine, whereby the side of the cast, hydratedalkaline detergent composition not surrounded by said receptacle-shapedcontainer is contained within the interior of said detergent dispensingdevice and is oriented to provide the interior of said detergentdispensing device with essentially one unsurrounded, exposed, drainablesurface of cast, hydrated, alkaline detergent composition; (b) impinginga spray of aqueous liquid from said spray means upon said unsurrounded,exposed, drainable surface to dissolve detergent composition at agenerally consistent rate and thereby form an aqueous liquid detergentcontaining said detergent composition in the aqueous liquid, whichaqueous liquid detergent .[.rains.]. .Iadd.drains .Iaddend.downwardlyfrom said unsurrounded, exposed, drainable surface generallysimultaneously with said impinging; (c) generally simultaneouslypermitting the downwardly-draining aqueous liquid detergent to flow outof said detergent dispensing device and into said warewashing zone forthe purpose of washing alkaline detergent-resistant ware .[.wherein.]..Iadd.therein.Iaddend.; and (d) controlling the duration of said step(b), thereby controlling the amount of said aqueous liquid detergentcomposition flowing into said warewashing zone, thereby controlling theconcentration of said detergent composition in said warewashing zone.12. A method according to claim 11 wherein said unsurrounded, exposed,drainable surface generally faces toward said spray means.
 13. A methodaccording to claim 12 wherein said cast, hydrated alkaline detergentcomposition is placed in accordance with said step (a) in an invertedposition above said spray means, such that said unsurrounded, exposed,drainable surface faces downwardly toward said spray means.
 14. A methodaccording to claim 11 wherein, in said step (a), said cast, hydrated,alkaline detergent composition is placed in an inverted position oversaid spray means, and said impinging is provided by a spray orientedgenerally perpendicularly to said unsurrounded, exposed, drainablesurface. .Iadd.15. A detergent-containing article of commercecomprising:(a) a three-dimensional, uniform solid cast, hydrated,alkaline warewashing detergent comprsing:(1) at least 30% by weight ofan alkaline hydratable chemical consisting essentially of alkali metalhydroxide; (2) an effective amount of a condensed phosphatehardness-sequestering agent; and (3) water of hydration, at least aportion of said water of hydration being associated with said alkalimetal hydroxide wherein the alkali metal hydroxide and the condensedphosphate hardness sequestering agent are present in amounts sufficientto render the cast detergent solid at room temperature by virtue of saidwater of hydration; and (b) a receptacle-shaped disposable containersurrounding and in contact with said solid, cast, hydrated alkalinewarewashing detergent composition on all but one surface thereof..Iaddend. .Iadd.16. An article according to claim 15 wherein thecontainer is made of a thermoplastic material and wherein the containeris a mold in which said alkaline detergent was cast and solidified..Iaddend. .Iadd.17. An article according to claim 15 wherein saidarticle further comprises a cover attached to the said receptacle-shapedcontainer mold. .Iaddend. .Iadd.18. The article of claim 15 wherein theweight of the alkali detergent is at least 6 lbs. .Iaddend. .Iadd.19.The article of claim 15 wherein the hardness sequestering agent is asodium tripolyphosphate compound. .Iaddend. .Iadd.20. An articleaccording to claim 15 wherein said solid, cast, hydrated, alkalinedetergent composition comprises:(a) at least about 30% by weight of thealkaline hydratable chemical consisting essentially of sodium hydroxide;(b) an effective hardness-sequestering amount of a sodiumtripolyphosphate compound; (c) an effective hardness sequestering amountof a polyelectrolyte; and (d) up to 5% by weight of an additive selectedfrom the group consisting of a defoamer and a solid, availablechlorine-containing component; wherein the alkaline detergent is castwithin the disposable container. .Iaddend. .Iadd.21. The article ofclaim 20 wherein the polyelectrolyte is an organic polyelectrolytecomposition. .Iaddend. .Iadd.22. A detergent-containing article ofcomprising a three-dimensional, uniform, solid cast, hydrated alkalinewarewashing detergent comprising:(a) at least about 30% by weight ofsodium hydroxide; (b) a second alkaline hydratable chemical comprisingan effective hardness-sequestering amount of sodium tripolyphosphate;(c) water of hydration in both discrete and continuous states ofhydration; (d) an effective hardness sequestering amount of apolyacrylate; and (e) up to 5% by weight of an additive selected fromthe group consisting of a defoamer and a solid, availablechlorine-containing component;wherein the alkali metal hydroxide and thehardness sequestering agent are present in amounts sufficient to renderthe cast detergent a solid at room temperature by virtue of the water ofhydration and the alkaline warewashing detergent is surrounded by andheld in contact with a receptacle-shaped disposable thermoplasticcontainer, on all but one surface thereof. .Iaddend. .Iadd.23. Anarticle according to claim 22 wherein said article further comprises acover attached to said receptacle-shaped container. .Iaddend.